A printed circuit board includes a circuit pattern formed on an insulating layer, and thus a variety of electronic parts may be mounted on the printed circuit board.
For example, the electronic parts mounted on the printed circuit board may be heating elements. Heat emitted by the heating elements may degrade the performance of the printed circuit board. With the realization of high integration and higher capacity of electronic parts, there is an increasing concern about heat dissipation problems of printed circuit boards.
To improve the heat dissipation performance, a heat dissipation sheet having a foam structure formed by a plurality of cells is proposed (Korean Unexamined Patent Application Publication No. 2004-0039090). The inside of the foam structure is filled with an inorganic filler having good thermal conductivity. Such a heat dissipation sheet is attached to a heating element to perform a thermal conduction function.
However, since the foam structure has excellent thermal insulation performance, there is a limit to the thermal conduction function of a heat dissipation sheet having the foam structure. Therefore, a method of enhancing a thermal conduction effect by minimizing pores is required.